cmd/compile: only sort methods/interfaces during export for -d=unifiedquirks
cmd/compile: only sort methods/interfaces during export for -d=unifiedquirks

These sorts are only important for 'toolstash -cmp' testing of unified
IR against -G=0 mode, but they were added before I added
-d=unifiedquirks to allow altering small "don't care" output details
like this.

This CL should help mitigate issues with #44195 until package
objectpath is updated and deployed.

Change-Id: Ia3dcf359481ff7abad5ddfca8e673fd2bb30ae01
Reviewed-on: https://go-review.googlesource.com/c/go/+/343390
Trust: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>
Run-TryBot: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>

cloudflare/go,nawawi/go,golang/go,CAFxX/go,golang/go,CAFxX/go,cloudflare/go,CAFxX/go,CAFxX/go,nawawi/go,cloudflare/go,cloudflare/go,nawawi/go,nawawi/go,cloudflare/go,golang/go,cloudflare/go,nawawi/go,CAFxX/go,nawawi/go,golang/go,golang/go,cloudflare/go,nawawi/go,CAFxX/go,CAFxX/go,cloudflare/go,golang/go,golang/go,golang/go,nawawi/go,CAFxX/go